In the manufacture of patterned textiles, and particularly in the manufacture of tufted textile products, designs are created for fabrics in a pixel-mapped format where each pixel in a graphic representation corresponds to a separate tuft or bight of yarn that is displayed on the surface of the tufted carpet. Pixel-mapped designs became prevalent as a result of the evolution of tufting machines to possess the capability of placing a particular color of yarn at virtually any location in a given pattern. In the field of broadloom tufting machines, this capability was present in the mid to late 1990s with computer controlled needle bar shifters, servo motor driven backing feeds, and servo motor driven yarn feed pattern controls. However, even decades earlier simple patterns could be tufted in a similar fashion as typified by Hammel, U.S. Pat. No. 3,103,187 using photo-electric cells to read instructions for actuation of electromagnetic clutch operated yarn feeds.
Other types of tufting machines such as hollow needle machines manufactured by Tapistron, or the Colortron machines manufactured by Tuftco Corp. have the ability to place any color of yarn in any location of the backing fabric. Independent control needle (“ICN”) machines typified by Cobble's ColorTec machines, also could place any color yarn at any position on backing fabric from about 1994.
Tufted textile fabrics may be manufactured from a single color of yarn threaded in all the needles of a tufting machine. However, in commercial and hospitality markets, it is much more common that patterns will have between about three to six colors of yarn, and in some cases, even more. When using multiple colors of yarn in a pattern, it often happens that some colors are utilized more heavily than others and particular needles on the tufting machine may utilize more of one color yarn than is utilized by a different needle tufting even the same color. These variations in yarn consumption can lead to inefficiencies.
The production of completed tufted textiles generally involves several distinct steps. First is the selection or creation of a pattern. Second is the tufting of a fabric by placing the yarns in a backing fabric according to the pattern. Finally, there are finishing steps to remove irregularities, to lock the tufted yarns in place with the application of a secondary backing, and to trim any uneven margins as the fabric is cut to size.
The creation of tufted fabric involves feeding yarns to needles on a tufting machine, and reciprocating the needles to insert the yarns through the backing fabric. By controlling operations such as the shifting of needles, the feeding of the backing fabric, the amounts of yarn fed to specific needles, the types of knives and gauge parts operating to seize or cut yarns carried through the backing fabric, and in the case of ICN tufting machines, the selection of needles to penetrate the backing fabric, almost any design can be created on a properly configured and threaded tufting machine.
It can be seen that the inputs necessary to create the tufted fabric include labor, yarn, backing fabric and the typically multi-million dollar investment in a tufting machine and yarn creel. Such tufting machines, while built on a chassis not unlike those from the last century, now include sophisticated electronics and software in addition to the many precision reciprocating and electronically driven parts that operate to move the yarns and backing as required.
With the evolution of tufting machines, the possibilities for patterns have evolved from solids, textures, geometrics, repeated graphics, and copies of woven textiles, to encompass nearly photographic representations of a wide range of images. Furthermore, patterns may now be over 1000 positions in both width and length, leading to designs with over a million individual pixel-mapped positions. In modern designs, carpet patterns that have organic or natural aspects, perhaps with the appearance of fallen leaves or similar designs inspired by nature or entropy, have emerged as desirable for many large spaces.
Since a tufting machine is a sizable fixed investment that should justify its cost over several years of production, the opportunities to minimize the overall cost of creating tufted fabrics must focus on the labor and materials consumed in that production. Labor is involved in creating designs and in configuring tufting machines for each individual pattern to be run, especially the threading of yarns to the individual needles and positioning of yarn cones in a yarn creel or the winding of beams to feed the yarns to the needles.
In addition, there is wasted yarn when patterns do not utilize similar amounts of colors of yarn fed to needles across the width of the tufting machine. This leads to two inefficiencies. First, if for example a red yarn is fed to a needle on the right side of the tufting machine and will consume a three pound yarn cone over the course of production of a pattern while a red yarn fed to a needle in the center of that machine will consume a four pound yarn cone, some compromise must be made. Either four pound yarn cones are placed in all positions on the creel for red yarns or three pound and four pound yarn cones must be prepared and positioned in appropriate places on the creel to feed yarns to the appropriate needle. In the former case, an extra pound of yarn will be left on the cones that were associated with needles only using three pounds of red yarn and that yarn will need to be salvaged. In the latter case, additional labor, with increased possibilities of improper configuration of the yarn creel, is injected into the configuration process.